title: Macrolide and aminoglycoside antibiotic resistance mutations in the bacillus subtilis ribosome resulting in temperature-sensitive sporulation.
abstract: Mutants of Bacillus subtilis resistant to various macrolide antibiotics have been isolated and characterized with respect to their sporulation phenotype and the electrophoretic mobility of their ribosomal proteins (r-proteins). Two types of major alterations of r-protein L17, one probably due to a small deletion, are found among mutants exhibiting high-level macrolide resistance. These mutants are all temperature-sensitive for sporulation (Spots). Low-level resistance to some macrolides is found to be associated with minor alterations in r-protein L17. These mutations do not cause a defective sporulation phenotype. All of the macrolide resistance mutations map at the same locus within the Str-Spc region of the B. subtilis chromosome. Hence, changes in a single ribosomal protein can result in different sporulation phenotypes. Mutants resistant to the aminoglycoside antibiotics neomycin and kanamycin have been isolated. Approximately 5% of these are Spots. Representative mutations, neo162 and kan25, cause concomitant drug resistance and sporulation temperature-sensitivity and map a single-site lesions in the Str-Spc region of the chromosome. Strains bearing neo162 or kan25 are equally cross-resistant to streptomycin or spectinomycin. These mutations define a new B. subtilis drug resistance locus at which mutation can cause defective sporulation.
mesh_terms: D000617:Aminoglycosides / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001412:Bacillus subtilis / Q000235:genetics* / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics; D004352:Drug Resistance, Microbial; D009154:Mutation; D010641:Phenotype; D012269:Ribosomal Proteins / Q000235:genetics; D013171:Spores, Bacterial
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D012269:Ribosomal Proteins